Effective Dechlorination of 2-Chloropropene to Propylene on a Metallic Nickel Catalyst Supported on y-Alumina

We previously reported that the reductive conversion of 2-chloropropene (2-PEN) on y-alumina-supported pal-ladium catalysts showed high activity at 348 K. However, 2-chloropropane (2-PAN), propylene, and propane were produced non-selectively in this catalyst system, so industrial development would require separation process. In the present study, an alumina-supported nickel catalyst achieved a highly selective conversion of 2-PEN to pro-pylene. For example, the propylene selectivity reached 95.7 % and conversion of 2-PEN was 15.0 % on the cata-lyst loaded with 10 % nickel at 473 K. However, the propylene yield was only 14.3 %, so the reaction was examined at 623 K, which resulted in 75.6 % conversion of 2-PEN and 78.6 % selectivity to propylene, with an adequate 59.4 % yield. Importantly, no propane was produced under these conditions, eliminating the need to separate propane and propylene. We concluded that by using nickel as a catalyst, an excessive reduction of pro-pylene to propane could be suppressed.